Use the Nvidia Control Panel (Right click on Desktop> Click on “Nvidia Control Panel”), go to “Manage 3D Settings” under the “3D Settings” tab on the top right of the window.
Then click “Add Program”, select the exe file of Rust (which should be in “Program Files(x86)\Steam\Steamapps\common\Rust\experimental”). In the Control Panel, make sure that the “2. Select the preferred graphics processor for this program:” and choose your NVIDIA GTX 750Ti.
Sometimes the rust launcher/game won’t pick up that you chose the better GPU rather than your integrated GPU(which I’m assuming you have, they’re pretty much on all Intel CPU computers).
You can also use the Nvidia Control Panel to set the settings more efficiently, or you can also opt to using Nvidia Inspector (after following the steps I posted above) to set more settings to better work with Rust. Try looking up “rust experimental Nvidia Inspector” and try out other people’s recommended settings to run the game smoothly.
Otherwise wait for more patches and such.